It turned out to be loose connectors. I just disconnected all cables and connected them again and all is well.

While the CD is playing fine, I think something is not right with the clamper setting. Couple of reasons -

1. It takes a long time for the CD player to read the disc and display the track numbers.

2. During the initial read, there is lot of screeching sounds and also sounds like the CD is hitting something.

3. The CD when spinning seems to wobble a lot, its not spinning in a stable manner. I am amazed that the player still reads the disc.

I tried adjusting the height of the brass shaft on the cam wheel but got mixed results. There were setting where the CD was not being read at all and then there were times where CD played fine without the screws on the CD mech but failed when screws were put back.

Any ideas ?

Thanks Jacques !! Yes, I did come across the posts for the motor but didn't go in that direction. I thought I was missing something during my belt change process.

I opened a CD4500 last night (just to see the CD spin) and noticed that the spinning CD was much smoother on CD4500. Seems like the CD is not centered in the CD 50 mechanism.

I will try the motor fix next.

And THANK YOU for all your posts. Appreciate the effort you take in spreading your knowledge.

But the CD should be clamped firmly too. It shouldn’t wobble at all. 

Yes Jacques. The CD is clamped firmly. Initially I thought that was the issue but I checked and clamping is fine.

See video (btw - knocking sound in video is me pressing the panel for next track) -